The present invention relates to a solution for processing, inclusive for use of a dedicated apparatus therefor, of a silver halide black-and-white negative recording film material suitable for being printed as motion picture soundtrack on a motion picture print film.
Motion picture print film, the film that is shown in movie theaters, commonly employs an optical analog soundtrack along an edge of the film. During projection of the motion picture images, a light source illuminates the analog soundtrack and a photosensor senses the light passing through and modulated by the soundtrack to produce an audio signal that is sent to amplifiers of the theater sound system. While the most common soundtracks are of the xe2x80x9cvariable areaxe2x80x9d type wherein the signal is recorded in the form of a varying ratio of opaque to relatively clear area along the soundtrack, xe2x80x9cvariable densityxe2x80x9d soundtracks are also known wherein the absolute density is uniformly varied along the soundtrack. Common sound systems incorporate a cell in the projector whose radiant sensitivity peaks at approximately 800-950 nm (depending on the type of photodiode), which detects the predominant infra-red (IR) radiation emitted by common tungsten lamps or red LED""s (light emitting diodes).
Digital soundtracks for motion picture films have been more recently introduced, wherein sound information is recorded in a digital format, e.g. comprising small data bit patterns on the film, typically between perforations of the motion picture film (e.g., Dolby(copyright) Digital Stereo soundtracks) or along the film edge (e.g., Sony(copyright) Dynamic Digital Sound soundtracks). U.S. Pat. No. 4,600,280 and 4,461,552, e.g., disclose methods in which digital audio is photographically recorded on motion picture film.
In order to optimize the visual quality of the motion picture image and to improve sound quality of the soundtrack recorded on a motion picture print film after having been printed from the sound negative film, the motion picture and soundtrack are first typically captured or recorded on separate photosensitive films as negative images, wherein the color negative film is characterized by a low contrast in order to provide large exposure latitude, opposite to the black-and-white sound recording negative film material characterized by a high contrast in order to sharply represent sound differences. Both resulting negatives are then printed in synchronization on a motion picture print film in order to form positive images. On account of the very short exposure times which must be given to each separate picture, or frame, in capturing a motion picture image, a camera negative film employing relatively fast silver halide emulsions is typically used to record the motion picture images. In order to reproduce the wide ranges of colors and tones which may be found in various images, the camera film typically also has a relatively low contrast or gamma. Variable area analog soundtracks and digital soundtracks, however, are best recorded with high contrast, relatively slower speed films in order to generate desired sharp images for the sound recording and minimize background noise generated by relatively high minimum densities typically associated with relatively fast camera negative films. Simultaneously printing of a digital and an analog soundtrack moreover requires an adapted filtering differing from each other during the printing process.
Sound recording films typically comprised of silver-based black-and-white films thus remain preferred. Said film is designed to be processed with conventional black-and-white developer solutions to form silver-based black-and-white images, such as, e.g. the D-97 process as specified in Module 15 titled xe2x80x9cProcessing black-and-white filmsxe2x80x9d of the Kodak Publication H-24 titled xe2x80x9cManual for Processing Eastman Motion Picture Filmxe2x80x9d. In such processes, after exposure, black-and-white images are generally produced by developing silver halide in a black-and-white developer containing a developing agent in order to form a silver image by reducing the exposed silver halide to silver metal. The undeveloped silver halide is removed from the film by xe2x80x9cfixingxe2x80x9d with aqueous fixer solution having a silver salt dissolving agent. The silver metal remaining in the film represents the image.
A well-known disadvantage of the classically applied D-97 processing chemicals is, besides its long developing time of about 4 to 5 minutes, its lack for stability in laboratories, opposite to stability obtained for color processing in well-experienced standardized color processing labs. The chemical developing solutions are not provided as ready-for-use solutions and should be prepared in the processing laboratory, thereby requiring trained people and an adapted environment, wherein chemicals can be handled without risk for environmental disasters.
Moreover digital soundtracks used in an increasing amount nowadays, are more sensitive to differences in developer compositions (from batch to batch and/or during processing) and there is lack for experience with replenishing measures applied by sound labs. The need to provide a constant quality for black-and-white processing of the sound recording negative film material puts an ever lasting load on the laboratory worker (requiring quite a lot of experience). As quite huge amounts of developer replenisher solutions (in the range form 500 to 650 ml per square meter of film material) are required, the load of the environment is also questionnable.
As a quick and absolute need for quality of digital soundtracks is a xe2x80x9cmustxe2x80x9d nowadays, it is clear that, in order to provide a black-and-white silver halide motion picture sound recording film comprising a support bearing at least one silver halide emulsion layer, spectrally sensitized with a first sensitizing dye providing a peak sensitivity at less than or equal to 600 nm and a second sensitizing dye providing a peak sensitivity above 600 nm, wherein the contrast overall gradient of the film is greater than 3.7, it is not evident that making use of fine monodispersed silver halide grains is sufficient in order to reach the desired image quality in the sound recording film, thus providing a soundtrack having high quality after having been printed on the color positive print film material.
It is an object of the present invention to provide a processing method and an apparatus for applying said processing method to a sound recording negative-working silver halide photographic film material in order to guarantee stable processing conditions leading to a constant sensitometry for the said sound recording film characterized by a perfectly constant contrast, thus enhancing image quality, translated as sound after having been printed said sound recording film onto a cine color print film material.
It is a further object of the present invention to provide the processed film after having been run in a rapid processing cycle in order to save time and money, as moreover, there is no need of transport to separate tone developing labs.
It is another object of the present invention to provide ability to perform said processing in an office environment, in a compact customer-friendly processing machine, further providing ability to processing in a daylight environment.
Still another object of the present invention is to provide daylight loading from camera to processor, therefore providing the sound recording film in a cassette, said film further having excellent antistatic properties.
A still further object of the present invention is to provide an ecologically more justified processing method, in order to avoid load of the environment by making use of a film coated with lower amounts of silver halide, further requiring lower amounts of chemicals in developer and fixer as well as in their corresponding replenishers.
Other objects of the present invention will become apparent from the detailed description and from the examples hereinafter.
The above mentioned objects have been realized by making use of a processing method having the specific features defined in the main independent claim. Specific features for preferred embodiments of the invention are set out in the dependent claims.
Further advantages and embodiments of the present invention will become apparent from the following description.